SUPPLEMENTAL CASH FLOW INFORMATION (Details) $ in Millions		12 Months Ended
	Jan. 05, 2018 USD ($) drilling_unit	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Supplemental Cash Flow Information [Line Items]
Number of Rigs Purchased at Auction | drilling_unit	2
Capital Expenditures Incurred but Not yet Paid		$ 42.2	$ 21.4	$ 21.0
Interest Paid, Excluding Capitalized Interest, Operating Activities		153.9	150.2	159.2
Income Taxes Paid, Net		$ 33.1	30.0	$ 38.1
P-60 [Member]
Supplemental Cash Flow Information [Line Items]
Purchase Price of Rigs Won at Auction	38.5
P-59 [Member]
Supplemental Cash Flow Information [Line Items]
Purchase Price of Rigs Won at Auction	38.5
P-59 and P60 Rigs [Member]
Supplemental Cash Flow Information [Line Items]
Purchase Price of Rigs Won at Auction	77.0
Security Deposit			$ 7.7
Purchase Price of Rigs Won at Auction less Deposit	69.3
Transaction Costs	$ 1.5